As buildings tend to become larger and higher, building fire often leads to a large scale accident. That's why fire-fighting criteria tend to become reinforced, and non-flammable properties and fireproofing criteria of building finish materials and other facilities are also being reinforced.
Fireproofing paint is the paint used to coat flammable materials including wood, foam sponge and plastic so that ignition may be prevented or ignition time delayed. Such fireproofing paint has two types including that based on fireproofing materials and that result in foaming upon heating to make a shield layer in-between a fireproofing material to shield flame and delay conduction of heat.
The former is prepared by addition of various pigments, non-flammable powder, etc. to fireproofing materials including fireproofing or non-flammable resins and chlorine compounds. The latter is prepared by adding various fire-resistant agents, foaming agents, insulating carbonization agents, carbonization promoters, etc. and using synthetic resins as its binder so that heating results in thermal degradation of a coating and generation of non-flammable gas and that an insulation layer formed by foaming in the shape of sponge of a few centimeters in thickness delays transfer of flame and heat to a flammable material.
The composition for forming non-flammable coating of the invention belongs to the latter. The existing fireproofing paint that belongs to this class, upon contacting flame by its coating, causes its coating ingredient to undergo physical and chemical changes by heat so that the coating under a carbonized state swells as a result of foaming and expansion and plays the role of protecting a base (flammable material) so that it may not be combusted by flame and heat. That is, for the foaming fireproofing paint that is currently used, the binder in the coating composition plays the role of a protective film and forms a carbonized foaming film that swells like sponge by the actions of expanding pigment, fireproofing agent, etc. added in the paint. While it is required to apply a thick coating to form a fireproofing coating with such foaming fireproofing paint, single application effort does not result in the coating of a sufficient thickness so it usually requires applications two to three times. However, if such foaming fireproofing paint is an aqueous base one, low volatility of water results in a low drying rate so that it takes much time to be able to undertake the second application following the first application. Therefore, the existing aqueous foaming and fire-proofing paint is poor in terms of workability. In addition, the aqueous foaming and fireproofing paint is aqueous so that microorganisms may breed easily, which results in the problem of poor long-term storage.
On the other hand, the ethylene-vinyl acetate copolymer emulsion is widely used for construction paint applications, and as the regulations on atmospheric discharge of organic solvents become much stricter, replacement with water-based paints is taking place in the fields where organic solvent based paints have been used. Nevertheless, the water-based paint has disadvantages in terms of water resistance and mechanical properties compared with the organic solvent based paint.